CATALOGUE OF GEMS AND PRECIOUS STONES. 115 



New Mexico. 

 Cerrillns, Sinta Fe County: 



Cabochon, elliptical girdle; blue-green; 26.90 carats; 28 by 18 by 7 mm. 



(fig. 12, pi. 12) No. 650 



Cabochon, elliptical girdle; blue-green; 18.54 carats; 23 by 18 by 6 mm. 



Gift of Dr. Robert H. Lamborn No. 652 



Cabochon, elliptical girdle; pale blue-green; 13.99 carats; 24 by 16 by 



6 mm. Gift of Dr. Robert Lamborn No. 653 



Cabochon, circular girdle; green-blue; 9.355 carats; 14 by 7 mm. Gift 



of American Turquoise Company No. 655 



Cabochon, elliptical girdle; green-blue; 7.69 carats; 16 by 10 by 6 mm. 



Gift of American Turquoise Company No. 657 



Cabochon, elliptical girdle; green-blue; 5.38 carats; 14 by 9 by 6 mm. 



Gift of American Turquoise Company No. 658 



Cabochon, circular girdle; green: 4.95 carats; 16.5 by 3 mm. Gift of 



American Turquoise Company No. 659 



Cabochon, elliptical girdle; green-blue; 4.7 carats; 20 by 9 by 4 mm. 



Gift of American Turquoise Company No. 656 



Cabochon, elliptical girdle; green-blue; 4.16 carats; 12 by 10 by 5.5 mm. 



Gift of American Turquoise Company No. 660 



Cabochon, elliptical girdle; blue-green; 3.79 carats; 16 by 8 by 4 mm. 



Gift of American Turquoise Company No. 661 



Nine matrix stones, eight elliptical, one circular girdle; one pale blue; 



eight blue-green; total weight, 55.48 carats; 20 by 13 by 6 to 11 by 



5 by 3.5 mm. Gift of H. P. Petersen No. 651 



Carved arrowhead mounted as a scarf pin; blue-green; 22 by 9 mm No. 654 



LOCALITY NOT RECORDED. 



Carving in imitation of a frog; green-blue; 0.635 carat; 6 by 5 by 3 mm. 

 Gift of O. T. Jonassohn No. 1087 



Unakite. — See under Miscellaneous (Granite) on page 120. 



VARISCITE. 



Synonym. — Utahlite. 



Composition. — Hydrous aluminum phosphate, A1(P0 4 ) + 2H 2 0. 



Crystallization. — Orthorhombic ; distinct crystals rare, the material 

 being usually crypto-crystalline. 



Color. — Green to blue-green, owing to the presence of chromium or 

 vanadium, or both. 



Luster. — Vitreous; translucent to opaque. 



Hardness. — 4; not a durable stone under ordinary conditions of 

 wear. 



Specific gravity. — 2.40 ±0.05. 



Optical properties. — Mean refractive index, 1.55; double refraction 

 moderate, 0.02; optically biaxial. 



The mineral may be distinguished from turquois, which it sometimes 

 closely resembles, by its more greenish color and less hardness, and 

 from other gems which resemble it, by chemical tests. It occurs 

 filling fissures and cavities in rocks high in aluminum, mostly in shale 

 or slate (pi. 13). In use it is usually cut cabochon because of its 

 practically opaque character. Of less value than turquoise. . 



